Spinlock.h

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
 
#ifndef KERNEL_SPINLOCK_H
#define KERNEL_SPINLOCK_H
 
#include "pedigree/kernel/SpinlockWord.h"
#include "pedigree/kernel/compiler.h"
#include "pedigree/kernel/processor/types.h"
 
class EXPORTED_PUBLIC Spinlock {
  friend class PerProcessorScheduler;
  friend class LocksCommand;
 
 public:
  Spinlock();
  Spinlock(bool bLocked, bool bAvoidTracking = false);
 
  bool acquire(bool recurse = false, bool safe = true);
 
  void exit(uintptr_t ra = 0);
 
  void release();
 
  bool acquired();
 
  bool interrupts() const;
 
  static const bool allow_recursion = true;
 
 private:
  bool acquireContended(bool recurse, bool safe, uintptr_t ra) NEVER_INLINE;
 
  void unlock(uintptr_t ra) ALWAYS_INLINE;
 
  void unwind() ALWAYS_INLINE;
 
  volatile processor_register_t* deferredReleaseWord();
  void unlockForScheduler();
 
  void trackRelease(uintptr_t ra) const;
 
  uintptr_t acquisitionAddress() const;
  void badMagic(uintptr_t ra) const NEVER_INLINE;
  void badReleaseInterrupts() const NEVER_INLINE;
  void deadlock(uintptr_t ra, bool releasing, uintptr_t acquiredAt = 0) NEVER_INLINE NORETURN;
 
  NOT_COPYABLE_OR_ASSIGNABLE(Spinlock);
 
  SpinlockWord m_Lock;
  bool m_bInterrupts = false;
 
#if SPINLOCK_DIAGNOSTICS
  uint64_t m_Sentinel = 0;
  uint32_t m_Magic = 0xdeadbaba;
  uint32_t m_MagicAlign = 0;
  uintptr_t m_Ra = 0;
#endif
 
  void* m_pOwner = nullptr;
  size_t m_Level = 0;
  size_t m_OwnedProcessor = ~0;
 
  bool m_bAvoidTracking = false;
};
 
#endif